This powder coating production line is designed for spraying carbon
steel sheets of various dimensions and shapes used in safes.
The spray booth is constructed with PVC panels, and the coating
application combines both automatic spray guns and supplementary
manual touch-up spraying. The pretreatment section runs on a
skid-type ground conveyor, while the powder coating section
operates on an overhead conveyor system that maintains a constant
conveying speed.
Production Line Workflow
1. Welding Area Loading
A robotic manipulator places the cabinet body and door panel onto
two independent work positions.
2. Metal Grinding
A robotic grinding unit polishes the weld seams on the cabinet
body.
Door panel weld seams are manually polished, followed by
full-surface manual sanding to ensure a smooth finish.
3. Phosphating Solution Treatment
Operators manually wipe the surfaces with a phosphating agent to
improve coating adhesion and corrosion resistance.
4. Moisture Drying
The treated workpieces are dried at 40–50°C to remove any remaining
moisture.
5. Manual Putty Application
Technicians apply putty to fill surface imperfections and ensure
surface flatness.
6. Putty Drying
The putty layer is dried at 40–50°C to achieve proper hardness.
7. Manual Putty Sanding
After curing, the putty is manually sanded to obtain a uniform,
smooth finish.
8. Workpiece Accumulation
Finished parts are accumulated—approximately 100 sets—before
entering the next stage.
9. Mechanical Loading Transfer
The accumulated workpieces are automatically transferred to the
next process via mechanical loading equipment.
10. Dust Removal
Operators use electrostatic dust blow guns to remove dust and fine
particles from the surface.
11. Powder Coating Application
A combination of automatic spraying and manual reinforcement is
used to ensure full and even coverage.
12. Powder Curing
The coated parts are cured at 200°C for 18 minutes, allowing the
powder coating to fully crosslink and solidify.
13. Air Cooling
After curing, parts undergo forced air cooling to stabilize the
coating.
14. Manual Installation of Casters
Casters are manually attached to the finished cabinet bodies.
15. Assisted Downloading to AGVs
Using human–machine collaborative handling, the completed units are
placed onto AGV carts for transfer to the next workstation.
